<style>
.welcome{
	position:absolute;
	top:40%;
	left:50%;
	-moz-transform:translate(-50%,-50%);
	transform:translate(-50%,-50%);
}

.window{
	position:absolute;
	top:40%;
	left:50%;
	-moz-transform:translate(-50%,-50%);
	transform:translate(-50%,-50%);
	width:1200px;
	background-color:red;
}
</style>
<div class="window">
	<img class="welcome" src="images/641.png" />
</div>

